In the printing industry one long existing problem has been the problem of "streaking" in the printed product. One commonly held belief is that streaking is caused by the variation in pressure between a cooperable pair of plate and blanket cylinders as the gaps in the outer surfaces of the plate and blanket cylinders come into registry with each other. The prior art has extensively reviewed the streaking problem such that a repetitious detailed description thereof is not warranted for an understanding of the present invention to one skilled in the relevant art. However, the prior art is informative in that it emphasizes not only the streaking problem, but also sets forth many of the factors which can cause streaking such as the speed of a printing press, the configuration of the cylinders of a printing press, cylinder mounting, the bearing supports for the cooperable plate and blanket cylinders, etc. U.S. Pat. No 3,395,638 is of interest as a non-circular blanket or impression cylinder is described having a relief area 50 of a width w to provide a force characteristic (FIGS. 3a and 3b) whereby vibration of the cylinders is reduced. This patent also describes the effects of the sudden application and release of an impression force, and comments upon the complications of critical speed resonance, printing press speed, the gap or gutter on the cylinders, and non-printed margin. U.S. Pat. No. 3,166,012 is of interest in that a skewed gap is defined to maintain an uninterrupted compression gripping pressure on a web passing through a pair of cooperable blanket cylinders. In such patent the skew angle is quite small, illustratively 0.3 degrees on a 36 inch blanket. In obtaining such minimum angle the stated governing relationship is that the skew "advance" or arc B (FIG. 3) shall be significantly greater than the gap width minus the width of the narrow zone of tangency T. Thus, for a minimum skew angle, as desired, the skew advance is always less than the gap width. See for example the illustrative numerals set forth in the patent. U.S. Pat. No. 4,125,073 also sets forth the streaking problem with reference to the gap or gutter and cylinder vibration. This patent also comments upon the degradation of oscillatory cylinder movement, blanket resilience, lack of ink transfer and the relative oscillations of the plate and blanket cylinders. In such patent a mechanical damping mechanism is disposed in one or more cylinders to reduce cylinder oscillation. This patent further illustrates the well known nature of mechanical damping means for minimizing cylinder oscillation. U.S. Pat. No. 4,149,461 describes a cam and cam follower structure to prevent objectionable streaking.
Still other aspects of the prior art are shown in U.S. Pat. Nos. 3,256,812--re bearer rings; 3,177,804--re positive guiding; 3,589,285--re controlled yieldable portion; 2,986,085--re offset or displaced gaps, and 2,812,134--re blanket seam and margin. In addition the prior art disclosed and/or discussed in the above patents should be examined to obtain a complete understanding of the streaking problem.